In Japanese folklore shussebora are giant sea snails that transform into yokai when they reache advanced age. It is believed that they first live under mountains until they are about 3000 years old. Then during landslides they descend to villages where they live for another 3000 years. Finally they burrow their way to the sea and live for another 3000 years before transforming into a type of sea dragon. There is an unlikely rumour that eating their flesh can ensure you have a long life.

🎨Matthew Meyer (via yokai.com)